By BBR test and Burgers model analysis, the low temperature performance of different kinds of SBS modified asphalt under different aging process were analyzed. It had been proved that asphalt viscoelastic characteristics match the PG low temperature grading system well. Analysis results also show that short term aging process is favorable to low temperature performance of radial SBS modified asphalt and SBS modified asphalt shows deficiency with respect to creep rate. Quantitative analysis of aging influence on functional groups based on Fourier transform infrared spectroscopy(FTIR) are also conducted. The correlation between various physical and chemical indexes is discussed. It indicates that the smaller aliphatic long chain index is, the better low temperature performance SBS modified asphalt shows.